When using loops in a program it is important to have $1)$ A condition that can actually be reached, and $2)$ If in a for loop, incrementation.

If you have a while loop that exits the loop when active $=$ false, somewhere in the loop there must be a conditional statement that will make active false, otherwise you will be stuck in an infinite loop and crash your program. In a for loop if your loop does not iterate properly you will also create an infinite loop for $($int i $=0$; i $>=0$; i$++)$ will never exit since i is always going to be greater than or equal to $0,$ the proper condition to check for would be i $>=0$ and decrement to $-1.$

Two loops that you will see in many programs are the while loop and the for loop. A while loop can be used to loop through code while a condition is true. If you are writing a game, you would use a while loop to update every input or frame, depending on what kind of game you are making. A for loop increments through a quantity. So if you wanted to check for spaces in a string you could create a for loop that increments through every character in the string that looks for character a space character $""$ and run some code when that condition is met.